From c14a8fbfef00269dd24dc3d5960bb777eae8e198 Mon Sep 17 00:00:00 2001
From: Karsten Schmidt <k@postspectacular.com>
Date: Sat, 13 Mar 2021 11:03:04 +0000
Subject: [PATCH] refactor(dcons): dedupe OOB error handling

---
 packages/dcons/src/dcons.ts | 17 ++++++-----------
 packages/dcons/src/sol.ts   |  4 ++--
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/packages/dcons/src/dcons.ts b/packages/dcons/src/dcons.ts
index a1f9df65f3..c887a32ba5 100644
--- a/packages/dcons/src/dcons.ts
+++ b/packages/dcons/src/dcons.ts
@@ -1,5 +1,4 @@
-import {
-    assert,
+import type {
     Comparator,
     Fn,
     IClear,
@@ -12,12 +11,12 @@ import {
     ISeq,
     ISeqable,
     IStack,
-    Predicate,
+    Predicate
 } from "@thi.ng/api";
 import { isArrayLike } from "@thi.ng/checks";
 import { compare } from "@thi.ng/compare";
 import { equiv } from "@thi.ng/equiv";
-import { illegalArgs } from "@thi.ng/errors";
+import { ensureIndex, illegalArgs } from "@thi.ng/errors";
 import { IRandom, SYSTEM } from "@thi.ng/random";
 import { IReducible, isReduced, ReductionFn } from "@thi.ng/transducers";
 
@@ -223,7 +222,7 @@ export class DCons<T>
         if (n <= 0) {
             return this.cons(x);
         } else {
-            this.ensureIndex(n);
+            ensureIndex(n, 0, this._length);
             return this.insertBefore(this.nthCellUnsafe(n), x);
         }
     }
@@ -235,7 +234,7 @@ export class DCons<T>
         if (n >= this._length - 1) {
             return this.push(x);
         } else {
-            this.ensureIndex(n);
+            ensureIndex(n, 0, this._length);
             return this.insertAfter(this.nthCellUnsafe(n), x);
         }
     }
@@ -307,7 +306,7 @@ export class DCons<T>
             if (at < 0) {
                 at += this._length;
             }
-            this.ensureIndex(at);
+            ensureIndex(at, 0, this._length);
             cell = this.nthCellUnsafe(at);
         } else {
             cell = at;
@@ -640,10 +639,6 @@ export class DCons<T>
         return [...this];
     }
 
-    protected ensureIndex(i: number) {
-        assert(i >= 0 && i < this._length, `index out of range: ${i}`);
-    }
-
     protected nthCellUnsafe(n: number) {
         let cell: ConsCell<T>, dir: keyof ConsCell<T>;
         if (n <= this._length >> 1) {
diff --git a/packages/dcons/src/sol.ts b/packages/dcons/src/sol.ts
index 075602a775..9cbfebcd68 100644
--- a/packages/dcons/src/sol.ts
+++ b/packages/dcons/src/sol.ts
@@ -1,5 +1,5 @@
 import type { Fn2, Predicate } from "@thi.ng/api";
-import { illegalArgs } from "@thi.ng/errors";
+import { outOfBounds } from "@thi.ng/errors";
 import { ConsCell, DCons } from "./dcons";
 
 /**
@@ -44,7 +44,7 @@ export class SOL<T> extends DCons<T> {
 
     setNth(n: number, v: T) {
         const cell = this.nthCell(n);
-        !cell && illegalArgs(`index out of bounds: ${n}`);
+        !cell && outOfBounds(n);
         this._reorder(this, cell!).value = v;
         return this;
     }